58 PROCEEDINGS OF THE NATIONAL MUSEUM vol.74 



joints brown ; middle and hind tarsi brown from the tip of the first 

 joint; joints of fore tarsi as 41-18-16-5-8; of middle ones as 44r-26- 

 20-10-9; joints of posterior pair as 36-45-30-18-12. Calypters and 

 halteres yellow, the former with black cilia. 



Wings gray, rather narrow; first vein reaching half way to the 

 cross vein; third vein straight; last section of fourth vein abruptly 

 bent beyond its middle, then arched so as to be parallel with third 

 vein and running quite close to it for some distance at tip ; cross vein 

 19, last section of fifth vein eighteen-fiftieths of a millimeter long. 



Female. — Face about twice as wide as in the male and with its 

 sides parallel; third antennal joint mostly brown; palpi and proboscis 

 yellowish ; middle tibiae with two bristles below ; otherwise about as 

 in the male. 



Described from one male and one female taken by J. M. Aldrich. 

 May 7, 1926, at Quirigua, Guatemala. 



^2/^6.— Male, Cat. No. 41069, U.S.N.M. 



Genus PELASTONEURUS Loew 



Pelastoneurus Loew, Neue Beitr., vol. 8, 1861, p. 36; Hon. North Amer. 

 Diptera, pt. 2, 1864, p. 103, table of species. — Aldrich, Kansas, Univ 

 Quart., vol. 2, 1893, p. 152 ; Biologia Central Amer., Diptera, vol. 1, 1901, 

 p. 336, table of Mexican species ; Kansas Univ. Sci. Bull., vol. 1, 1902, p. 

 47, table of species. — Wheeleb, Proc. California Acad. Sci., vol. 2, 1896, 

 p. 11, table of species. — Van Duzee, Ann. Ent. Soc. Amer., vol. 16, 1923, 

 p. 44, table of species. 



PELASTONEURUS CAERULEUS Van Dnzee 



Pelastoneurus caeruleus Van Duzee, Annals Ent. Soc. of America, vol. 16, 

 1923, p. 37. 



This species was described from Guatemala. J. M. Aldrich took 

 two males. May 1, 1926, at El Salto, Antigua ; one female. May 7, at 

 Quirigua; and three females, April 14 and 16, at La Providencia, 

 Obispo, all in Guatemala. Nathan Banks took one female, August 8, 

 1924, at Bella Vista, Panama. 



PELASTONEURUS MACULITIBIA, new species 



Male. — Length, 4.2 mm. Face wide, grayish white, more white 

 below, suture below the middle; front violet on the sides, blackish in 

 the middle; palpi black with a narrow yellow margin; antennae 

 black, first two joints very slightly reddish yellow below, third joint 

 nearly circular, not quite as long as wide ; arista feathered with long 

 hairs ; lateral and inferior orbital cilia silvery white. 



Dorsum of thorax shining brown with green reflections, dulled 

 with brown pollen; pleurae more black with silvery-white pollen; 



